Ontogeny of foraging site fidelity in two sympatric marine predators: a mother and pup perspective

Abstract

Foraging experience of juveniles is less diverse and inferior to that of adults. The knowledge gained during their first foraging phase after gaining independence is important to not only individual survival but also population subsistence. However, the ontogeny of naïve individuals’ foraging behaviour is poorly understood. The Marion Island sympatric fur seal population, consisting of Subantarctic (Arctocephalus tropicalis; SAFS. and Antarctic (Arctocephalus gazella; AFS. fur seals have colony-specific foraging areas and maintain minimal overlap with foragers from neighbouring colonies situated around the coastline of Marion Island, despite being well within the travelling range of each other. How these segregated foraging areas of breeding colonies develop is currently unknown. Mother-pup pairs of two SAFS colonies on the west and north-east respectively and one AFS breeding colony on the south coast of Marion Island were satellite tracked. These locations coincide with previously satellite tracked study colonies. The aims were: 1. to determine whether pups forage with their mothers in the same areas after weaning; and 2. to determine whether pups forage in the same general broad colony-preferred foraging areas than their adult colony-counterparts. Unsurprisingly, pups from all 3 study colonies did not forage with their mother post-weaning. However, AFS pups on the south coast, SAFS pups from the west and north-east coast of Marion Island all foraged in the same general south, west and north-east directions as their respective adult colony-counterparts. This suggests that colony-preferred foraging areas, and subsequent foraging site fidelity, is not a learned behaviour as previously thought; but could either be 1. innate or 2. some form of information transfer exists between individuals within the colony. This is the first ever data where mothers and pups were tracked concomitantly and provide novel insights into the development of foraging memory. - Abstract as displayed in the - Abstract booklet. The presentation on the day may differ from the - Abstract.